A transtibial prosthesis is an artificial limb that replaces a leg missing below the knee. Transtibial amputees are usually
able to regain normal movement more readily than someone with a transfemoral amputation, due in large part to retaining the knee,
which allows for easier movement.

Transfemoral Prosthesis

A transfemoral prosthesis is an artificial limb that replaces a leg missing above the knee. Transfemoral amputees can have a
very difficult time regaining normal movement. In general, a transfemoral amputee must use approximately 80% more energy to walk
than a person with two whole legs. This is due to the complexities in movement associated with the knee. In newer and more
improved designs, after employing hydraulics, carbon fibre, mechanical linkages, motors, computer microprocessors, and innovative
combinations of these technologies to give more control to the user.

Transradial Prosthesis

A transradial prosthesis is an artificial limb that replaces an arm missing below the elbow. Two main types of prosthetics ar
available. Cable operated limbs work by attaching a harness and cable around the opposite shoulder of the damaged arm. The other
form of prosthetics available are myoelectric arms. These
work by sensing, via electrodes, when the muscles in the upper arm moves, causing an artificial hand to open or close.

Transhumeral Prosthesis

A transhumeral prosthesis is an artificial limb that replaces an arm missing above the elbow. Transhumeral amputees
experience some of the same problems as transfemoral amputees, due to the similar complexities associated with the movement of the
elbow. This makes mimicking the correct motion with an artificial limb very difficult.

2.5.1 Guide Dogs vs. Canes

For some, a long cane is an effective way to probe the physical environment and move around safely. Other people find that a guide
dog better suits their day-to-day travel needs. The choice is a personal one which involves careful consideration of lifestyle and travel
factors. Using a long white cane allows someone who is blind to locate steps, curbs, streets, driveways, doorways, bicycles, elevators,
escalators, people, chairs, tables, desks, or any other object or place. The cane is long enough to be about two steps ahead of the
person's feet, and so the walker finds objects with the cane before hitting them. There are canes of all sizes, including very small ones
for children and long ones for tall people. Some blind people like to use a guide dog to get around. These dogs are especially trained to
move around obstacles, go through doorways, and stop at curbs and stairs. When the blind person hears that it is safe to cross the street,
he or she will tell the dog to go ahead. And when the blind person gets to the address of the restaurant or business, the dog will find
the door. The blind person using the dog is always in charge and must tell the dog what to do.

People with service animals
sometimes face discrimination from business owners who do not know the law. In the United States especially, there are extensive legal
protections for service animals under the Americans with Disabilities Act (ADA). According to the ADA, a service animal must be allowed everywhere its owner is, and shall not be treated as a
“pet” by business owners. This law supersedes local ordinances, which may, for example, prohibit dogs from restaurants. Failure to admit
someone with a service animal into a business or workplace is grounds for a very serious lawsuit.

2.5.3 What is a Service Animal?

A service animal is an animal which has been specially trained to assist an individual with disabilities. Common examples of service
animals include guide dogs and horses, therapy animals,
and animals which pull wheelchairs or otherwise assist people with mobility impairments. Service animals are an important part of life for
their disabled partners, who have more independence and freedom thanks to their service animal companions. In addition, most nations have
laws protecting the rights of service animals, along with people with disabilities.

In order to be considered a service
animal, an animal needs to be individually trained to provide a service. Many service animals are also registered with a service animal
organization and a state or national service animal registry, but this is not required. The training for a service animal represents
months of work, as the animal must be trained to be good natured and obedient in a variety of situations, while also protecting its owner.
Service animals are taught to perform tasks such as looking out for traffic when their owners are blind, or alerting a deaf owner to a
potential hazard. At the same time, a service animal is taught “intelligent disobedience,” meaning that it will refuse to carry out an
order which it believes is dangerous.

While some breeds of animal are favored more than others for service, the primary concern
is the animal's temperament. Dogs, for example, are chosen for being friendly, easy to handle, loyal, and patient. Typically, a potential
service animal undergoes extensive behavioral testing before being accepted into a training program. Above all, a service animal is
not a pet, although the animal is probably loved by its owners. If you see someone with a service animal, always ask for permission
before petting or handling it, and be aware that if the animal is working, you may not be allowed to touch it.

In addition to
service animals assisting people with obvious disabilities, such as blindness, other service animals work as comfort or therapy animals.
Some of the most famous therapy animals have been unusual species, like chickens. A therapy animal can either work in a hospital or
clinical location helping a large number of patients, or be assigned to work with a specific person. Studies undertaken by organizations
like the Humane Society of the United States indicate that working with animals really does make people feel better, and this is the goal
of a therapy animal.

People with service animals sometimes face discrimination from business owners who do not know the law. In
the United States especially, there are extensive legal protections for service animals under the Americans with Disabilities Act.
According to the ADA, a service animal must be allowed everywhere its owner is, and shall not be treated as a “pet” by business owners.
This law supersedes local ordinances, which may, for example, prohibit dogs from restaurants. Failure to admit someone with a service
animal into a business or workplace is grounds for a very serious lawsuit.

2.5.3 What is a TTY?

A TTY is also known as a TDD (Telecommunications Device for the Deaf)

HOW IT WORKS:

This device 'rings' via flashing light or the more recent vibrating wrist band that resembles a watch. The TTY consists of a
keyboard, which hold somewhere from 20 to 30 character keys, a display. screen, and a modem. The letters that the TTY usre types
into the machine are turned into electrical signals that can travel over regular telephone lines. When the signals reach their
destination (in this case another TTY) they are converted back into letters which appear on a display screen, are printed out on
paper or both. Some of the newer TTYs are even equipped with answering machines.

WHO USES IT:

The TTY has 4 million users nationwide. 3 million of tese users are hearing impaired and the other 1 million have severe
speech impairments.

ADVANTAGES:

Without a means of Telecommunication, the deaf were, in a sense, isolated from many people and services. Life without a
telephone substitute involved many miles of driving to deliver and relay messages. (Which was very time consuming and
frustrating.) The TTY gives deaf people the luxury of just being able to pick up the phone and chat. It also provided an easier
way to connect to police and fire stations in case of emergency. And with the later creation of MRCs (message relay centers) the
TTY users could connect to any phone anywhere in the world.

DISADVANTAGES:

TTY users must know how to type. The alarmingly high spelling error rate of 5-6% (10% of which is TTY machine realted as in
the misfunction of a key) sometimes causes a problem in communication. One half million of TTY users communicate using ASL
(American Sign Language) or which there is no written counterpart. ASL also has a grammatical system which differs greatly from
that of Standard English. If a TTY user is especially "chatty", the other party must just sit quietly until the "
chatty" person sends the message, which they must then read and respond to. A conversation such as this would end up taking
much longer than the average phone call.

COST:

$300-$600 depending on what type of model you purcahse. (source: Communications of the ACM May 1992 v35 n5 p80)TTYs
(TDD)can be rented from US West for five dollars a month.

MRC (Message Relay Centers) Minnesota

HOW THEY WORK:

A hearing caller who needs to get in touch with a TTY user yet does not possess a TTY of his own can use a MRC to make his
call. The caller simply calls MRC (1-800-627-3529 - TTY or voice). The operator at the center will use a TTY to call the party
that the hearing person is trying to reach. The operator acts as an interpeter, typing the heaing person's message into a TTY and
reading the response to him as it returns. (This works vice versa for a deaf caller trying to reach a hearing party.)

ADVANTAGES:

The deaf can connect to any phone anywhere at any time. Their communicatiuon is no longer limited to other TTY users. It
opened up many services including mail order catalogs.